21620500415753 has 4 divisors (see below), whose sum is σ = 22147829694228. Its totient is φ = 21093171137280.

The previous prime is 21620500415749. The next prime is 21620500415771. The reversal of 21620500415753 is 35751400502612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7418666980729 + 14201833435024 = 2723723^2 + 3768532^2 .

It is a cyclic number.

It is not a de Polignac number, because 21620500415753 - 2² = 21620500415749 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 527329278433 = 21620500415753 / (2 + 1 + 6 + 2 + 0 + 5 + 0 + 0 + 4 + 1 + 5 + 7 + 5 + 3).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21620500415753.

It is not an unprimeable number, because it can be changed into a prime (21620500415713) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 263664639176 + ... + 263664639257.

It is an arithmetic number, because the mean of its divisors is an integer number (5536957423557).

Almost surely, 2^{21620500415753} is an apocalyptic number.

It is an amenable number.

21620500415753 is a deficient number, since it is larger than the sum of its proper divisors (527329278475).

21620500415753 is an equidigital number, since it uses as much as digits as its factorization.

21620500415753 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 527329278474.

The product of its (nonzero) digits is 252000, while the sum is 41.

The spelling of 21620500415753 in words is "twenty-one trillion, six hundred twenty billion, five hundred million, four hundred fifteen thousand, seven hundred fifty-three".